lib/VMCore/Module.cpp

   1 //===-- Module.cpp - Implement the Module class ---------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file was developed by the LLVM research group and is distributed under
   6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file implements the Module class for the VMCore library.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/Module.h"
  15 #include "llvm/InstrTypes.h"
  16 #include "llvm/Constants.h"
  17 #include "llvm/DerivedTypes.h"
  18 #include "llvm/ADT/STLExtras.h"
  19 #include "llvm/ADT/StringExtras.h"
  20 #include "llvm/Support/LeakDetector.h"
  21 #include "SymbolTableListTraitsImpl.h"
  22 #include <algorithm>
  23 #include <cstdarg>
  24 #include <cstdlib>
  25 #include <iostream>
  26 #include <map>
  27 using namespace llvm;
  28
  29 //===----------------------------------------------------------------------===//
  30 // Methods to implement the globals and functions lists.
  31 //
  32
  33 Function *ilist_traits<Function>::createSentinel() {
  34   FunctionType *FTy =
  35     FunctionType::get(Type::VoidTy, std::vector<const Type*>(), false);
  36   Function *Ret = new Function(FTy, GlobalValue::ExternalLinkage);
  37   // This should not be garbage monitored.
  38   LeakDetector::removeGarbageObject(Ret);
  39   return Ret;
  40 }
  41 GlobalVariable *ilist_traits<GlobalVariable>::createSentinel() {
  42   GlobalVariable *Ret = new GlobalVariable(Type::IntTy, false,
  43                                            GlobalValue::ExternalLinkage);
  44   // This should not be garbage monitored.
  45   LeakDetector::removeGarbageObject(Ret);
  46   return Ret;
  47 }
  48
  49 iplist<Function> &ilist_traits<Function>::getList(Module *M) {
  50   return M->getFunctionList();
  51 }
  52 iplist<GlobalVariable> &ilist_traits<GlobalVariable>::getList(Module *M) {
  53   return M->getGlobalList();
  54 }
  55
  56 // Explicit instantiations of SymbolTableListTraits since some of the methods
  57 // are not in the public header file.
  58 template class SymbolTableListTraits<GlobalVariable, Module, Module>;
  59 template class SymbolTableListTraits<Function, Module, Module>;
  60
  61 //===----------------------------------------------------------------------===//
  62 // Primitive Module methods.
  63 //
  64
  65 Module::Module(const std::string &MID)
  66   : ModuleID(MID), DataLayout("") {
  67   FunctionList.setItemParent(this);
  68   FunctionList.setParent(this);
  69   GlobalList.setItemParent(this);
  70   GlobalList.setParent(this);
  71   SymTab = new SymbolTable();
  72 }
  73
  74 Module::~Module() {
  75   dropAllReferences();
  76   GlobalList.clear();
  77   GlobalList.setParent(0);
  78   FunctionList.clear();
  79   FunctionList.setParent(0);
  80   LibraryList.clear();
  81   delete SymTab;
  82 }
  83
  84 // Module::dump() - Allow printing from debugger
  85 void Module::dump() const {
  86   print(std::cerr);
  87 }
  88
  89 /// Target endian information...
  90 Module::Endianness Module::getEndianness() const {
  91   std::string temp = DataLayout;
  92   Module::Endianness ret = AnyEndianness;
  93
  94   while (!temp.empty()) {
  95     std::string token = getToken(temp, "-");
  96
  97     if (token[0] == 'e') {
  98       ret = LittleEndian;
  99     } else if (token[0] == 'E') {
 100       ret = BigEndian;
 101     }
 102   }
 103
 104   return ret;
 105 }
 106
 107 void Module::setEndianness(Endianness E) {
 108   if (!DataLayout.empty() && E != AnyEndianness)
 109     DataLayout += "-";
 110
 111   if (E == LittleEndian)
 112     DataLayout += "e";
 113   else if (E == BigEndian)
 114     DataLayout += "E";
 115 }
 116
 117 /// Target Pointer Size information...
 118 Module::PointerSize Module::getPointerSize() const {
 119   std::string temp = DataLayout;
 120   Module::PointerSize ret = AnyPointerSize;
 121
 122   while (!temp.empty()) {
 123     std::string token = getToken(temp, "-");
 124     char signal = getToken(token, ":")[0];
 125
 126     if (signal == 'p') {
 127       int size = atoi(getToken(token, ":").c_str());
 128       if (size == 32)
 129         ret = Pointer32;
 130       else if (size == 64)
 131         ret = Pointer64;
 132     }
 133   }
 134
 135   return ret;
 136 }
 137
 138 void Module::setPointerSize(PointerSize PS) {
 139   if (!DataLayout.empty() && PS != AnyPointerSize)
 140     DataLayout += "-";
 141
 142   if (PS == Pointer32)
 143     DataLayout += "p:32:32";
 144   else if (PS == Pointer64)
 145     DataLayout += "p:64:64";
 146 }
 147
 148 //===----------------------------------------------------------------------===//
 149 // Methods for easy access to the functions in the module.
 150 //
 151
 152 // getOrInsertFunction - Look up the specified function in the module symbol
 153 // table.  If it does not exist, add a prototype for the function and return
 154 // it.  This is nice because it allows most passes to get away with not handling
 155 // the symbol table directly for this common task.
 156 //
 157 Function *Module::getOrInsertFunction(const std::string &Name,
 158                                       const FunctionType *Ty) {
 159   SymbolTable &SymTab = getSymbolTable();
 160
 161   // See if we have a definitions for the specified function already...
 162   if (Value *V = SymTab.lookup(PointerType::get(Ty), Name)) {
 163     return cast<Function>(V);      // Yup, got it
 164   } else {                         // Nope, add one
 165     Function *New = new Function(Ty, GlobalVariable::ExternalLinkage, Name);
 166     FunctionList.push_back(New);
 167     return New;                    // Return the new prototype...
 168   }
 169 }
 170
 171 // getOrInsertFunction - Look up the specified function in the module symbol
 172 // table.  If it does not exist, add a prototype for the function and return it.
 173 // This version of the method takes a null terminated list of function
 174 // arguments, which makes it easier for clients to use.
 175 //
 176 Function *Module::getOrInsertFunction(const std::string &Name,
 177                                       const Type *RetTy, ...) {
 178   va_list Args;
 179   va_start(Args, RetTy);
 180
 181   // Build the list of argument types...
 182   std::vector<const Type*> ArgTys;
 183   while (const Type *ArgTy = va_arg(Args, const Type*))
 184     ArgTys.push_back(ArgTy);
 185
 186   va_end(Args);
 187
 188   // Build the function type and chain to the other getOrInsertFunction...
 189   return getOrInsertFunction(Name, FunctionType::get(RetTy, ArgTys, false));
 190 }
 191
 192
 193 // getFunction - Look up the specified function in the module symbol table.
 194 // If it does not exist, return null.
 195 //
 196 Function *Module::getFunction(const std::string &Name, const FunctionType *Ty) {
 197   SymbolTable &SymTab = getSymbolTable();
 198   return cast_or_null<Function>(SymTab.lookup(PointerType::get(Ty), Name));
 199 }
 200
 201
 202 /// getMainFunction - This function looks up main efficiently.  This is such a
 203 /// common case, that it is a method in Module.  If main cannot be found, a
 204 /// null pointer is returned.
 205 ///
 206 Function *Module::getMainFunction() {
 207   std::vector<const Type*> Params;
 208
 209   // int main(void)...
 210   if (Function *F = getFunction("main", FunctionType::get(Type::IntTy,
 211                                                           Params, false)))
 212     return F;
 213
 214   // void main(void)...
 215   if (Function *F = getFunction("main", FunctionType::get(Type::VoidTy,
 216                                                           Params, false)))
 217     return F;
 218
 219   Params.push_back(Type::IntTy);
 220
 221   // int main(int argc)...
 222   if (Function *F = getFunction("main", FunctionType::get(Type::IntTy,
 223                                                           Params, false)))
 224     return F;
 225
 226   // void main(int argc)...
 227   if (Function *F = getFunction("main", FunctionType::get(Type::VoidTy,
 228                                                           Params, false)))
 229     return F;
 230
 231   for (unsigned i = 0; i != 2; ++i) {  // Check argv and envp
 232     Params.push_back(PointerType::get(PointerType::get(Type::SByteTy)));
 233
 234     // int main(int argc, char **argv)...
 235     if (Function *F = getFunction("main", FunctionType::get(Type::IntTy,
 236                                                             Params, false)))
 237       return F;
 238
 239     // void main(int argc, char **argv)...
 240     if (Function *F = getFunction("main", FunctionType::get(Type::VoidTy,
 241                                                             Params, false)))
 242       return F;
 243   }
 244
 245   // Ok, try to find main the hard way...
 246   return getNamedFunction("main");
 247 }
 248
 249 /// getNamedFunction - Return the first function in the module with the
 250 /// specified name, of arbitrary type.  This method returns null if a function
 251 /// with the specified name is not found.
 252 ///
 253 Function *Module::getNamedFunction(const std::string &Name) const {
 254   // Loop over all of the functions, looking for the function desired
 255   const Function *Found = 0;
 256   for (const_iterator I = begin(), E = end(); I != E; ++I)
 257     if (I->getName() == Name)
 258       if (I->isExternal())
 259         Found = I;
 260       else
 261         return const_cast<Function*>(&(*I));
 262   return const_cast<Function*>(Found); // Non-external function not found...
 263 }
 264
 265 //===----------------------------------------------------------------------===//
 266 // Methods for easy access to the global variables in the module.
 267 //
 268
 269 /// getGlobalVariable - Look up the specified global variable in the module
 270 /// symbol table.  If it does not exist, return null.  The type argument
 271 /// should be the underlying type of the global, i.e., it should not have
 272 /// the top-level PointerType, which represents the address of the global.
 273 /// If AllowInternal is set to true, this function will return types that
 274 /// have InternalLinkage. By default, these types are not returned.
 275 ///
 276 GlobalVariable *Module::getGlobalVariable(const std::string &Name,
 277                                           const Type *Ty, bool AllowInternal) {
 278   if (Value *V = getSymbolTable().lookup(PointerType::get(Ty), Name)) {
 279     GlobalVariable *Result = cast<GlobalVariable>(V);
 280     if (AllowInternal || !Result->hasInternalLinkage())
 281       return Result;
 282   }
 283   return 0;
 284 }
 285
 286 /// getNamedGlobal - Return the first global variable in the module with the
 287 /// specified name, of arbitrary type.  This method returns null if a global
 288 /// with the specified name is not found.
 289 ///
 290 GlobalVariable *Module::getNamedGlobal(const std::string &Name) const {
 291   // FIXME: This would be much faster with a symbol table that doesn't
 292   // discriminate based on type!
 293   for (const_global_iterator I = global_begin(), E = global_end();
 294        I != E; ++I)
 295     if (I->getName() == Name)
 296       return const_cast<GlobalVariable*>(&(*I));
 297   return 0;
 298 }
 299
 300
 301
 302 //===----------------------------------------------------------------------===//
 303 // Methods for easy access to the types in the module.
 304 //
 305
 306
 307 // addTypeName - Insert an entry in the symbol table mapping Str to Type.  If
 308 // there is already an entry for this name, true is returned and the symbol
 309 // table is not modified.
 310 //
 311 bool Module::addTypeName(const std::string &Name, const Type *Ty) {
 312   SymbolTable &ST = getSymbolTable();
 313
 314   if (ST.lookupType(Name)) return true;  // Already in symtab...
 315
 316   // Not in symbol table?  Set the name with the Symtab as an argument so the
 317   // type knows what to update...
 318   ST.insert(Name, Ty);
 319
 320   return false;
 321 }
 322
 323 /// getTypeByName - Return the type with the specified name in this module, or
 324 /// null if there is none by that name.
 325 const Type *Module::getTypeByName(const std::string &Name) const {
 326   const SymbolTable &ST = getSymbolTable();
 327   return cast_or_null<Type>(ST.lookupType(Name));
 328 }
 329
 330 // getTypeName - If there is at least one entry in the symbol table for the
 331 // specified type, return it.
 332 //
 333 std::string Module::getTypeName(const Type *Ty) const {
 334   const SymbolTable &ST = getSymbolTable();
 335
 336   SymbolTable::type_const_iterator TI = ST.type_begin();
 337   SymbolTable::type_const_iterator TE = ST.type_end();
 338   if ( TI == TE ) return ""; // No names for types
 339
 340   while (TI != TE && TI->second != Ty)
 341     ++TI;
 342
 343   if (TI != TE)  // Must have found an entry!
 344     return TI->first;
 345   return "";     // Must not have found anything...
 346 }
 347
 348 //===----------------------------------------------------------------------===//
 349 // Other module related stuff.
 350 //
 351
 352
 353 // dropAllReferences() - This function causes all the subelementss to "let go"
 354 // of all references that they are maintaining.  This allows one to 'delete' a
 355 // whole module at a time, even though there may be circular references... first
 356 // all references are dropped, and all use counts go to zero.  Then everything
 357 // is deleted for real.  Note that no operations are valid on an object that
 358 // has "dropped all references", except operator delete.
 359 //
 360 void Module::dropAllReferences() {
 361   for(Module::iterator I = begin(), E = end(); I != E; ++I)
 362     I->dropAllReferences();
 363
 364   for(Module::global_iterator I = global_begin(), E = global_end(); I != E; ++I)
 365     I->dropAllReferences();
 366 }
 367